Flotation of minerals.



CLEMENT Li PERKINS, or PITTSBURGH,

RECOVERY comrA Y, or NEW YORK, N. Y., A

PENNSYLVANIA, ASSIGNOZR. 'ro METALS CORPORATION or MAINE.

FLOTATION' OF MINERALS.

No Drawing.

.771 ail whom it may concern:

Be it known that I, CLEMENT L. PERKINS, a citizen of the United States, residing at Pittsburgh, in the county of -.Allegheny,

State of Pennsylvania, have invented cer- Y tain new and useful Improvements in Flotation of Minerals, (Case 13;) andl do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. V

This invention relates to the concentration of minerals, such as sulfid ores and the like, (for example, chalcopyrite with a silicious gangue), by flotation, and is based upon the discovery that improved results can be obtained by carrying out the flotation operation with the addition to the ore or mineral pulp of xylidin (aminoxylene), either alone or with the addition of other agents promoting the flotation.

The xylidin may be used in the form of the commercial product which is made up of a mixture of theindividual xylidins. Such commercial xylidin can be used in its crude or unrefined state.

In using the xylidin it, may be-added to the ore either alone or in admixture with other agents promoting the flotation, in any suitable manner, so that it will be thoroughly and uniformly distributed throughout the ore pulp. The mixture is then subjected to a flotation operation as in-an ordinary Callow cell or in apparatus where the air is incorporated in the ore pulp by mechanical agitation. With some ore pulps itmay be desirable to add either small amounts of acids or of alkalis, depending upon the nature of the ore pulp to be treated, but it will be evident that free acid should not be present to any appreciable extent when the xylidin is added. That is to say, if the ore pulp contains free acid, or if acid is preliminarily added thereto, the free acid should not be present when the xylidin is added, or should not be present to any appreciable extent such as would prejudice or destroy the effect of the xylidin, which is of a basic character, during the flotation operation.

With some ore pulps it is important not' only to have no free acid present, but to Specification of Letters Patent. Patented Sept, Application filed August 2, 1917. Serial No. 184,054.

add suflicient free alkali to give a distinct alkaline reaction to the ore pulp during the flotation operation. Small amounts of caustic alkali, such as sodium hydrate, or of alkali salts, such as sodium carbonate, may thus be added, in regulated amounts, to give the ore pulp the proper degree of alkalinity.

The amount of xylidin used may vary somewhat for example, between one-half pound or less and one and'one-half pounds per ton of ore (that is, calculatedon the weight of the ore and It is characteristic of the invention that the froth obtained is readily broken up and the xylidin recovered therefrom so that it is available for use in the treatment of further amounts of ore. That is to say, the circuit water recovered from the concentrate and even that recovered from the tailings contains notable amounts of the xylidinwhich can thus be returned to theprocess with resulting economy in the amount required to be added for subsequent operations.

The xylidin may be used alone to promote the flotation operation and high grades of concentrates obtained; and the resultingconcentrates can be much more easily separated by filtration than the common concentrates obtained by the use of oil as the flotation agent. The action of the xylidin may, however, be modified orsupplemented by adding other agents (such as oils or nonoleaginous agents) which promote the flotation and which do not In applying the xylidin, it may be introduced into the tube mill in being ground, or it may be otherwise introduced into theore pulp in any suitable way, as, for instance, by dropping it into the ore pulp before it enters the flotation cell, or by first digesting it in hot water and mixing the product with the ore pulp just before it enters the flotation cell.

What I claim is:

1. The method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of xylidin, and subjecting the renot of the ore pulp) which the ore is prejudicially affect the action of the xylidin.

sultingmixture to a flotation operation; subtion of minerals by flotation, which com- 4 prises adding to the mineral pulp a small amount of xyhdln andother agents promoting the flotation, and subjecting the resultmg mixture to a flotation operation; substantially as described.

3. The method of effecting the concentrationof minerals by flotation, which comprises adding to the mineral pulp a small amount of Xylidin and suflicient alkali to give the ore pulp a distinct alkalinereaction and subjecting the resulting mixture to a flotation operation; substantially as described.

4. The method of effecting the concentra-,

ing the resulting mixture to a flotation operation; substantially as clescribed.

In testimony whereof I affix my signature.

. CLEMENT L. PERKINS. 

